Thursday, September 07, 2006

Recovery from the little ice age?

One argument often heard in the AGW debate goes something like this:

The Earth may be warming, but human activities are not responsible: Even if the Earth is warming, it is obviously part of the continuing recovery from the “little ice age,” the cool period from the fifteenth to eighteenth centuries.

This argument tacitly assumes that the Earth’s climate system has a “normal” state that it pushes back to after unusually warm or cold periods, like a stretched spring returning to its normal length. While this might appear commonsensical, it has no foundation in either the record of how climate has varied or the fundamental physics of the atmosphere. The Earth’s climate has no “normal” state to which the climate seeks to return, so there is no reason to expect that an unusually cool period will be followed naturally by a return to warmer conditions.

Rather, when interpreting cause-and-effect in the temperature record, one has to consider the forcings. One can make a strong argument based on solar proxies (like sunspots) that the increasing temperature between the 17th century to about the middle of the 20th century was due to increasing solar forcing.

However, for the particularly rapid warming of the late 20th century, we have a good knowledge of the forcings of the climate. As I described here, we can eliminate solar variability as a primary driver. In fact, the only forcing that explains the warming is the increase in greenhouse gases.

In summary, there is no evidence that today’s particularly rapid warming is caused by the same thing as caused most of the warming over the last few centuries. By considering the forcings, we can conclude that most of the recent warming can be attrbituted to human activities. Thus, the argument that today's warming is simply a continuation of some natural trend is unsupported by any science.

58 comments:

Dr, J
said...

Dr. D, I suppose you believe all the cyclical data of temps and CO2 content and regular frequency of the last 800,000 years as shown in the ice cores is wrong. I agree the earth's climate has no memory and has no prefered state, which is something you need to remember when those of your ilk argue for the last few 1000 years of alledged "stable" climate that was drastically alterned by man.

I am in agreement with the conventional wisdom that we've experienced episodic ice ages over the past few million years ... driven by orbital variations. I'm not sure why you'd presume I thought otherwise.

Well, perhaps I read this too quickly and with a jaundiced eye, but it appeared you were ruling out the cyclical nature of many things in nature (climate included), which is well established in the literature on almost any time scale, perhaps you should look at the well know sunspot and solar cycles for reference. The way you described it, like a spring snapping back, is misleading. The Little Ice Age (which your associate Dr. North apparently doesn't think happened) is a good example of cyclical temperature swings over less than geologic time scales, as was the Medieval Warm Period. One didn't cause the other, as in your spring analogy, but they certainly do, along with many other scale cycles of climate changes, show the distinctly cyclic nature of climate through earth's history. So what is your point again Dr. D? That the Little Ice Age did not cause the recent warming? I agree. That the recent warming is caused exclusively or primarily by man? I disagree and your spring analogy does not prove your point.

George, I really thought few scientists really believe in the goofy Gaia Theory.

My point is that cycles don't happen by themselves. They happen because something is causing them. Thus, one has to look at the forcings.

The idea that the recent warming is a continuation of warming from the little ice age through the early 20th century has no scientific support. Rather, the peer-reviewed evidence supports GHGs as the cause of most of the recent warming.

Surely you aware of the fact that the bot the little ice age and the mid. warm period were regional events not global? Yet the current changes are global.

I also wonder why you are so convinced that even though historical data presented on ice cores, CO2 is all not to be trusted yet somehow our historical knowledge regarding solar activity is just A OK? Because we have such accurate data on solar sport from 800,000 years ago?

Also, there is no problem is saying that the earth's climate has changed many times yet the past 1,000 years have been relatively stable.

Mr. Bloom, do you mean that Dr. Dessler can get our IP addresses and then get back to our personal data and information from our internet service provider? When I blog I have an expectation of privacy, now you are saying he and you want to violate that? Strange for you to say that Mr. Bloom and ask Dr. Dessler to do it.

Mark UK, yes again we disagree, but this time I don't understand your rant. I never said "(I) was convinced that even though historical data presented on ice cores, CO2 is all not to be trusted yet somehow our historical knowledge regarding solar activity is just A OK"Nor did I say: "Because we have such accurate data on solar sport from 800,000 years ago"Nor did I say:"that the earth's climate has changed many times yet the past 1,000 years have been relatively stable."This just doesn't make any sense, sorry if I misread your post, but you obviously misread mine.

Also, there is not sufficient evidence to say the Little Ice Age and Medieval Warm Periods were not global (there are peer reviewed papers that make the case both ways) , and if you think the current century of warming is actually global, perhaps you should check the 2001 IPCC report's Technical Summary, and look closely at the 4 maps on page 27, not only will you see warm and cool cycles through the last century, but you will see differences in the northern and southern hemispheres as well.

The difference between the Northern and Southern hemisphere has been so extensively documented...

You have made it quite clear in your posts that you do not believe the data from icecores to be accurate enough to explain changes in climate or levels of CO2.

You also state regularly that you believe solar activity and cosmic rays have been proven to be cause of these changes.

I am trying to find out why you believe the historical evidence for those last two is reliable...

Yes, Dr J you did not say:"that the earth's climate has changed many times yet the past 1,000 years have been relatively stable."

I was pointing out that there is no contradiction in this statement. rather than your statement:

"I agree the earth's climate has no memory and has no prefered state, which is something you need to remember when those of your ilk argue for the last few 1000 years of alledged "stable" climate that was drastically alterned by man."

No I didn't Mark UK. You are not reading very well today. I said none of those things, just repeat what I said and don't put your biased spin on it, then you will see what I said. But let's cut the crap, what is it you disagree with that I actually said (without your rewording and changing my meanings). This conversation will go faster without putting words and meanings in my mouth, since I didn't say them I don't understand them.

Mark UK, I missed your first "comment". If differences in temperatures north and south (sometimes up, sometimes down, and sometimes certainly cooler one place and warmer another) have been extensively documented, then why do they call it "global warming" since it is not warm over the entire globe at one time. I would think a more accurate term would be "regional warming" in someplaces and "regional cooling" in others. But I prefer accurate terms, others like general ones that convey a different tone suited to their agenda.

Are you color blind Dr. D? Do you see the BLUE dots that show COOLER temps on all theses maps (these are the same as the ones in the 2001 IPCC Technical Summary I referenced BTW), including the "last few decades". And the last few decades?? I thought you were all claiming a century or more of AGW, now it's only the last few decades? Intersting change of data sets. OK, but even looking at the last few decades (1976-2001), there are quite a few blue dots there, so what does that mean? Some places are cooler (or is this just bad data we can ignore), then is it truly "Global Warming"? What % of the earth's surface can be cooling for it still to be "global warming"? Is there a consensus on that? Maybe 10%, or 20%, or does it just have to be a majority of the earth's surface? Parsing words and data is a political game.

Global Warming does not mean "warming everywhere on the globe" it means "warming of the globally and seasonally averaged temperature". Thus some regions experiencing cooling is no contradiction to this.

The MWP was a European phenomenon and not pronounced enough to have influenced the globally averaged temperature a great deal. Did you think that everywhere on earth was warmer 1000 years ago than eerywhere on earth today? I would be interested in the evidence you have, if so. If not, then I am at a loss to understand what the MWP is and what it implies about today.

George, it is common for bloggers to note IP addresses, which are available to absolutely every website you ever request a page from, but this is not usually so they can find out personal info, rather it is to identify sock puppets.

OK, so global warming means " "warming of the globally and seasonally averaged temperature". Thus some regions experiencing cooling is no contradiction to this." I guess then the "globally and seasonally averaged temps" is not what the IPCC data is showing? Or is it?

Then I have to ask, when do we know that AGW is happening if some places are cooling and others warming? Where is that magic cut off for that determination and we know when it started, and thus how will we know when we have turned the tide and temps are finally cooling as we get rid of all that CO2? Is the answer in the temps, or just measure the CO2? The IPCC maps show distinct cooling from 1945-1975 (I know, I know, that can be explained by numerous short term things and humans were still responsible for global warming even over that period), and there was also a majority of warming, as distinct as the "last few decades", from 1900 to 1945, so was that also caused by human CO2 even though there wasn't much yet? So how do we see this distinct human CO2 signal and when did it start? 1880 (Ind. Revol.), 1910, when cars started spewing the satanic gas, or was it just the last few decades when SUVs took over? Sorry for the sarcastic tone, but you do see how nonsensical this whole argument is.

I don't think you can separate your human CO2 "noise" from the natural variations "signal" in the earth's complex and ever varying climate. Please don't refer me to the Mann hockey stick, we all know how discredited that work has become.

Coby, if you think the MWP is just Europe, perhaps you can explain the paleo-temps from corals in the southern hemisphere that also show it. Maybe you can explain the evidence from the Americas and Greenland of this warm period, and from Siberia. I admit the best evidence is from Europe, but that is where all the people and research data has been gathered, the number of proxies from other areas is sparse, but few show any cooling.

I see coby, so does that mean that these "sock puppets" are to be arrested or sued or exposed somehow and brought to justice as the angry Mr. Bloom suggests? Isn't it possible that large ISPs have thousands or more people with the same IP address?

so does that mean that these "sock puppets" are to be arrested or sued or exposed somehow

I'll take door number 3, "exposed somehow". Some people's IP's are fixed, some dynamic. A court conviction would require ISP logs, but sometimes looking and quacking like a duck is enough, and who needs the DNA.

But the basic concept is weighted averages of all weather stations and other sources (the weighting is to adjust for higher concentrations of stations in one region vs another).

As for your other gattling gun of questions, some have answers, some are ill-posed, but your pre-emptive conclusion hardly encourages me to take any time to answer you. It is always a risky thing to assume a whole field of science is non-sensical when you are not aware of even the most basic things in it.

New York Area: Pederson, D.C., Peteet, D.M., Kurdyla, D., Guilderson, T. 2005. Medieval Warming, Little Ice Age, and European impact on the environment during the last millennium in the lower Hudson Valley, New York, USA. Quaternary Research 63: 238-249.

There are blue dots on the plot, no doubt about it. However, my point is that the warming is occurring over the entire globe --- it's not a regional effect. I don't think the existence of a few blue dots challenges that point.

The regions that are cooling are interesting. I don't know whether they are bad data or some mode of variability of the atmosphere.

I gave you the blog links because it is my own and it is easier to gie a link rather than repeating, yet again, basically very straightforward and simple arguments. There are many direct sources cited there in as well, that was another reason I provided those links.

I did not see a single study of global temperatures in the list you provided, thanks anyway. You can not infer a global climate signal from a single region, or a set of cherry picked regional studies.

Have a look here (NCDC - NOAA) for some sources of global reconstructions as well as hemispheric and many regional ones, though it is pretty likely that you do not actually read these papers. If you don't wish to read them, there is no crime in that but you should accept then the conclusions as summarized by NOAA:

"The idea of a global or hemispheric "Medieval Warm Period" that was warmer than today however, has turned out to be incorrect."

Sorry Dr. D, I didn't see or remember that you said only the last few decades are the only time humans have altered climate with their CO2, if you think so you are a very rare and objective bird in this messy, polarized and political debate and I congratulate you for that. Many of your associates do not believe that, as far as I can tell at least from the rhetoric and previous studies and congressional tesimony, as well as the IPCC.

Coby, you said that the MWP was not global and there was no evidence beyond Europe, I contend there is tons of evidence beyond Europe that this warm period existed, and I offered you many peer review scientific papers whereas you offered me a slanted, biased blog with personal opinions aimed at debunking the Luddite skeptics (who they all know are stupid and oil industry stooges). Then you offered a bunch of references on a NOAA site I doubt you looked at (I know many quite well, many are from Mann and that is incorrect as shown by Wegman, et al) but take a look at many of them for the MWP period, you will see warm anomolies.

The papers I offered you all show MWP existed in the regions that were studied, thus there is evidence of the MWP beyond Europe. Perhaps you shouldn't trust generalized government sources with agendas without checking. We are fighting a stupid war today because people did that, use your brain, research, look, think and make up your own mind, don't trust the government to do all your thinking and conclusions for you.

Just for the record, the IPCC also clearly states that it is only the last few decades where human impacts are clear:"There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."That quote can be found here, about half-way down the page.

Interesting Dr. D, but when I read this in the "Summary for Policymakers" in the 2001 IPCC Report, it seems to be saying much more :" New analyses of proxy data for the Northern Hemisphereindicate that the increase in temperature in the 20th centuryis likely to have been the largest of any century during thepast 1,000 years."

And this also gave me pause to think IPCC considered AGW to be shown much longer in the temp records:"The global average surface temperature (the average of nearsurface air temperature over land, and sea surface temperature)has increased since 1861. Over the 20th century the increasehas been 0.6 ± 0.2°C"

All these seem to be enphasizing a long term warming of much more than the last few decades. Is it that they wrote the "Summary for Policymakers", also known as AGW for Dummies, to mislead? I think the last few decades is plausable and even possible to see a faint, human signal, but the IPCC does it's cause no good by gross exaggeration and misleading half truths.

Dr. Dessler, you might find this news story interesting about a new Senate bill introduced by Sen. Inhofe to drastically increase fines and enforcement on pollution. It seems Calif. and the Democrats are crying foul. Odd reaction for supposedly environmentally sensitive folks?

It seems Calif. and the Democrats are crying foul. Odd reaction for supposedly environmentally sensitive folks?

Why do you purvey FUD, George? The article clearly explains the reason for the cry of 'foul':

The bill drew an angry response from Sen. Barbara Boxer, D-Calif., ..."I can only conclude that this legislation is punishment for my state's groundbreaking, bipartisan global-warming bill,"...Frank O'Donnell, director of Clean Air Watch, called Inhofe's move "a political stunt by the Senate's biggest champion of big polluters."

"Sen. James Inhofe, R-Okla., produced a bill to more than double fines on polluters who don't meet cleanup deadlines for soot and smog. States that don't require polluters to clean up could be denied federal highway funds. California isn't mentioned in Inhofe's bill, but it applies to areas that don't meet strict attainment standards for ozone and particulate matter. The only two areas of the country that meet that description are the Los Angeles Basin and the San Joaquin Valley."

So somehow Inhofe wanting to bring Calif. into compliance with existing federal laws (all other states are) for actual pollution that kills people in real time and is a public health risk that taxpayers foot the bill for in medical costs, is punishment for Calif. passing a bill on AGW? So if Calif. industries have to meet the same regulations as the rest of the country that is unfair to Calif. industries, but it is OK for Calif. government to pass laws to regulate CO2 that no other state has and that is fair for Calif. industry? Your logic overwhelms me Dano.

I would think politically it would be better to call Inhofe's bluff, get behind it, pass the bill and I would be willing to bet that if industries in Calif. actually met the regulations on real pollution, their CO2 emissions would be cut more rapidly and deeper than the do nothing bill Arnie passed. The Democrats are missing a real opportunity to get something done, instead they are looking like hypocrites.

I readily accept Dr. Dessler's statement that there is not solid evidence that human activity caused global warming prior to the last several decades. However, I would appreciate Dr. Dessler's thoughts on a couple of recent papers that were published that call into question some of our recent conclusions about the relative impacts of certain forcings and the role played by some of the feedback loops.

I am specifically speaking about the recent finding by Katey Walter et al, that arctic lakes may be a much more significant source of methane than previously thought, so much so that the author suggests they could be a "positive feedback to global warming"; and the recent finding by Peter Strutton et al that flaws in our satellite measurements of plankton density in tropical waters may significantly overestimate the uptake of CO2 by those waters (by up to 2.5 billion tons per year). (Citations for these papers at the end of the post)

So if we all concede that we can't say for sure what caused the warming from 1860 to about 1940, and we are now finding out that we may have vastly underestimated the amount of methane produced by arctic lakes (which have enlarged in response to the warming since 1861 and would have increased their output as they enlarged), while at the same time, we may have significantly overestimated how much CO2 tropical oceans uptake, how are we so sure that our own input of GHG to the atmosphere is the most significant factor causing the current warming? The recent posts by Dr. D here have pointed out that the assumption that human activity has caused recent global warming has been arrived at by process of elimination where we ruled out other forcings that we thought were insignificant. At what point do we go back and look at some of these recent findings (including those I posted about before regarding changes in heat flux at the CMB) and realize that while we can argue whether there is consensus about whether humans are the most significant cause of global warming, we can't keep pretending that whatever consensus exists is based on a full and complete understanding of all of the processes involved.

Bottom line, the current "scientific consensus" for whatever that phrase is worth, is based on calculations derived from "our current understanding of the system"; and the reality is that "our current understanding of the system" as pointed out by the recent published findings of several researchers is inadequate to lead to scientific certainty given the error already inherent in all global climate models.

I certainly agree that politics is working here (my dad was, among other things, a lobbyist and campaign mgr.), on both sides. The Ds need to point out the game, and Inhofe needs retribution. That's how it works. Your solution is one way to go about it; the Ds have their way, which I don't necessarily agree with.

Bill F:

he reality is that "our current understanding of the system" as pointed out by the recent published findings of several researchers is inadequate to lead to scientific certainty given the error already inherent in all global climate models.

If you'll forgive me, this gobbledegook is cr*p.

Your premise that the conclusion of AGW is based solely on climate model output is false. The rest of your argumentation is based on similar false premises.

There is, simply, overwhelming evidence. You just don't want to see it, for whatever reason, hence the typical strained rationale.

There is a distinct difference between uncertainty and unpredictability. There is a whole specialist science around decision making. You do not need 100% certainty to make decisions. Governments and companies do this all the time.

I guess I'm not sure what you think is misleading in the IPCC report. The IPCC says:1) the Earth has been warming for centuries2) we can attribute most of the warming of the last 50 years to humansErgo, we cannot attribute warming before that to humans. Humans might be playing a role, maybe not. Our data are not sufficient.

Is that really unclear or misleading???? I have to be honest here: I don't know if you're seriously objecting to something or just trying to yank my chain. I actually hope the latter since I don't see anything to object to here.

OK, Mark UK, what then is the predictability of reducing CO2, by any actions drastic or otherwise, that will lead to a cooling of temperatures to the ideal level you have in mind (and is that 1, 2, 3, or 4 degrees F lower than today?)? I have also asked many pro-AGW foks what is the perfect temperature they wish to achieve with their interventions into the earth's climate, and it is hard to get an answer. Makes me wonder if that is not really the goal. So tell me what the ideal earth temp would be for you, and how predictable that is and what we will all need to do so you will be happy.

I posted citations to two peer-reviewed and published scientific papers. One provides research that shows that the inputs into our existing models for CO2 uptake by tropical oceans may be off by a significant margin. The second provided research to show that arctic lakes provide up to 5 times as much methane into the atmosphere as previously thought and clearly states their conclusion that the difference warrants consideration of the lakes as an important positive feedback to global warming. I didn't make any of that up and it isn't "gobbledegook cr@p". You and several others jumped all over me for not providing any basis for my skepticism on other threads. Now on multiple postings on several threads, I have provided papers and research by well known and award winning scientists showing that we don't understand the processes and inputs into the climate system as well as we think. Yet all you can come back with is to call it cr@p and rail on and on about "consensus" and false premises.

FWIW, I hate to argue with somebody who refuses to accept scientific evidence and debate its relevance, but here goes. I never said everything we know about global warming is based on climate models. What I said is that all climate models have built in error values that everybody knows about and accepts. Within that range of accepted error, if the model is able to successfully simulate a set of climate data using the inputs we give it, then we consider it to be potentially useful in predicting future climate based on predictions of the future inputs. However, what happens when a model predicts the current data correctly but then you find out later that one or more of the inputs or feedbacks included in the model is wrong by a significant margin? Do you ignore the errors and continue assuming that the model will correctly predict the future without modification? No! You go back and re-evaluate it with the correct initial inputs and corrected feedback values and then see if it still successfully recreates the known data set.

So with that in mind, lets work backwards to how we came to estimate man's contribution of greenhouse gases into the atmosphere. Do you really think somebody went out and measured the output of every stack in every country around the world? Did we measure the CO2 uptake of every tree and every ocean? Nope...we take what we think we know about industrial production levels and emissions rates, etc. for a given time period in a given country, and then extrapolate it out across all of the assumably significant source areas...then we look at what we know about non-human sources and processes and all of what we know about the feedbacks that increase or reduce GHG concentrations. With all that in mind, we essentially reach a SWAG (scientific wild a$$ guess). If our SWAG of human inputs over time matches the atmospheric concentrations in our models over that same period of time after we run through all of the feedbacks, then we assume our SWAG of human output is accurate. So what then happens to that estimate if we find out that what we thought was an insignificant source of GHGs is actually 5 times larger than we estimated and IS significant? What happens if we look at our estimate and recognize that we overestimated by 2.5 billion tons how much was taken out of the system by one of the processes? The potential error in the CO2 uptake of tropical oceans alone equals nearly 10% of the world's total emissions. I am not saying our estimate of how much we produce is off by that amount. I am saying that what we believe about the contribution of human CO2 emissions to the total atmospheric concentration is flawed if there is an extra 2.5 billion tons per year in the atmosphere that we thought was being absorbed by plankton. If you then add in arctic lakes producing 5 times the methane we previously estimated, then it calls into question what we know about how much of the total atmospheric concentration of GHGs is the result of human activity and how mush is from previously underestimated sources or misunderstood processes.

You can go on and on about what "the consensus" is, but the data I am talking about was published less than 30 days ago. So are you saying that every scientist who knows anything about global warming has taken this new data, matched it up with his or her own data, run it through models and calculations and published a peer-reviewed paper reaffirming his or her commitment to "the consensus" (since we are only allowed to consider peer-reviewed papers as evidence of legitimate scientific beliefs per your comments on another post)? That is alot of science to take place in less than 30 days...got any citations to back it up?

Look, I am not saying AGW is wrong. I am not saying human activities are not the most significant cause of climate change in the last three decades. Both of those statements may in fact turn out to be accurate. What I am saying is that I object to people claiming there is a consensus view that all "reasonable" scientists adhere to that is 100% supported by all legitimate published and peer-reviewed literature. That false statement is continually used to paint anybody who voices a skeptical opinion as a whacko oil-company lackey who is incapable of accepting reality. The "reality" is that just in the past 2 months, I can count at least 4 peer-reviewed papers that have been published in legitimate journals that provide data pointing out places in which our understanding of processes or even our raw data that we have based previous research, calculations, and modeling on is flat wrong. The authors don't use their papers as a platform to call into question broad theories about AGW, because that is not the point of their research. But the fact that they don't do that shouldn't be taken as automatic assumption that they concur with some "consensus" view derived by a literature search of papers that may be up to 10 to 20 years old and woefully out of date given the recent progress in research and data collection.

Before you respond to this post, go read those papers, ok? Then go read the discussion from a few weeks ago about the 2 year downward trend in oceanic heat content and the problems it poses for models that we use to explain heat flux between the ocean and the atmosphere. Then go read some of the papers I posted links to that discuss the possibility that changes in our understanding of the geodynamo may result in significant changes to the estimates of heat flux to the earth's surface from the core.

If you come away from that still 100% convinced that human activity is the only scientifically plausible explanation for global warming, fine. We can agree to disagree. But hopefully, after reading those papers, you will at least understand that my skepticism is not based in a refusal to accept "an inconvenient truth", but in genuine scientific doubt about how well we really understand the climate system of our planet. You are still welcome to disagree that I am justified in holding that skeptical view, but I hope that at least you can accept that is not skepticism from an uninformed viewpoint or doubt created by an unwillingness to face "reality".

Well Dr. D my natural skepticism and distrust of all things UN leads me to suspect that the preamble they put in the SFP was meant to create a sense of shock and awe about rapidly rising temps for a long period of time. The unspoken but implied linkage to these rising temps and human CO2 causing them is a little too intentional. If they had just said what you said, I would be fine with it, but I know the agenda they are trying to push, and thus exaggeration was the order of the day. Do you disagree that most of these "scientists" on IPCC (except of course the few that have objected to the SFP) were convinced long before the 2001 report was written that AGW was a fact and needs urgent action?

Risk analysis, cost-benefit analysis and prudent decison making are all well established. This has nothing to do with your pretty straw man argument of perfect temperature. You are a scientist? Do some research on this part of the debate before jumping to conclusions.

I am sure you are active in icecore research, you obviously are not in the decision making science...

Bottom line, the current "scientific consensus" for whatever that phrase is worth, is based on calculations derived from "our current understanding of the system"; and the reality is that "our current understanding of the system" as pointed out by the recent published findings of several researchers is inadequate to lead to scientific certainty given the error already inherent in all global climate models.

The argument here is either:

1. The two articles I cite here show we don't everything about the climate system.

or

2. The two articles I cite here show we don't know everything about the earth system.

Response:

1. The Beherenfeld et al. don't look at the climate system. Did you mean to cite something else? And the Walter et al.: we already know this is a feed back to the system. What's your point?

2. And? What's your point?

After looking at these two abstracts, I can only conclude they do nothing to support your argument.

I want to dissect your response a little, because you are still trying to fall back on unsubstantiated statements and disconnected ideas to "refute" what I am saying. First understand this...I am not trying to change your mind. If you are a scientist, you should have an open mind and be willing to accept new data and incorporate it into your own understanding of what you believe. It is not my place to tell you that you are right or wrong or to try to change what you believe. My goal is instead to open your eyes to the idea that there is a valid scientific basis for somebody to be skeptical (not dismissive...skeptical) of the "consensus" view that humans are the only scientifically possible source for the vast majority of the recent global warming. So lets get on with the dissection...

Your statement:But the italicized isn't how it works, either, as the consensus of scientific opinion doesn't say what you say.

My response:I didn't make any statement or claim about what the scientific consensus says. What I said was that reviewing papers that may be 10 years old or older for evidence of opposition to the "consensus" does not constitute defining the scientific opinion of an entire field. I presented two brand new scientific papers that raised serious doubts about our understanding of two significant factors affecting climate (non-anthropogenic GHG production and oceanic CO2 uptake). I used them not to try to overturn the consensus (or to change your mind about AGW), but to establish that doubt and uncertainty about the "consensus" understanding is based in peer-reviewed and published scientific research and that recent research is changing some of the things that the "consensus" has taken for granted for many years.

Your statement:Namely: it is that human activity is the major cause. That is: on top of any cyclic activity that may be happening now, human activity is changing the climate.

My response:I have never denied that humans could play a role or even that it may be a very significant one. I have simply expressed my doubts that we can determine with certainty how significant that role is or precisely when our influence became significant, when we don't understand the system well enough, as shown in the findings of the VERY recent papers that show that our estimation of oceanic CO2 uptake and arctic lake GHG production are simply WRONG.

Your statement:It's basic physical principles, see, and the AGW denialists have no testable hypotheses to show that increasing the atm CO2 ppmv 35% has no effect on global climate.

My response:I never said that increasing CO2 by 35% would not have any effect. My opinion is that it does have an effect, but 1) I don't agree that we have a good handle on how much of that 35% increase we caused, and 2) I don't know how much of the change in global temperature was caused by that 35% increase and how much the temperature caused the 35% increase (see the statement in the Walter paper about increased melting causing higher GHG production from the lakes and compare it to the recent paper that shows that glacial melting has been increasing since the late 1800s).

What I did provide were 2 VERY recent scientific findings showing that the "consensus" understanding of two "basic physical principles" was flat wrong. The arctic lakes finding is particularly interesting to me in that the previous "consensus" was that arctic lakes were an insignificant source of GHGs. That sounds very similar to a statement Dr. Dessler made to me on another thread a few days ago when he told me that climate scientists ignore changes in heat flux from the earth's core because the heat flux from the earth is believed to be insignificant relative to solar input. The consensus was dead wrong in their understanding of arctic lakes and their importance as GHG sources, and given the rapidly changing understanding of the geodynamo and suggestions in recent papers that core to surface heat flux may be much higher, the dismissal of core heat flux changes as an unimportant factor has the potential to be just as wrong.

You need to read what I am saying and stop trying to find a convenient label for me. I am not a "denialist". You claimed in previous threads that my skepticism was unsupported without peer-reviewed and published scientific research to back it up, so I have provided peer-reviewed and published research to point out how recent findings have shown the errors and uncertainty in the past beliefs of the "consensus".

Dano, The consensus is not magical. It isn't some mystical force that defies logic, reason, or scientific research. It is a mirage created by people who want to paint those who don't agree with them as outside of "mainstream" science. I could put any five "consensus" believers from the climate science world in a room together and they would have raging arguments and debates over aspects of the processes that drive global warming and the way in which we model them. They may all agree on a certain framework, but their individual theories and ideas would be no more similar than a group of five random aggies discussing why our football team has been outscored so many times in the last 3 years.

You continue to use the fact that I don't agree with the consensus as evidence that I have no basis for my skepticism, yet you haven't once tried to show that the concrete, scientifically researched RECENT findings that I have presented to justify why I am skeptical are false or have no influence on AGW. The flaw in all of your reasoning is your assumption that for somebody to say the consensus is not 100% correct, they have to show that it is 100% wrong or that some scientist has to come up with a complete soup to nuts alternative hypothesis that turns science on its head before there could be any scientific validity to disagreeing with the consensus. It is possible to disagree with the level of certainty and degree of accuracy of the "consensus" based on multiple papers showing that the data used and processes determined to be significant by the "consensus" are wrong or have serious flaws. Anybody who has ever worked with complex computer models will tell you that any small error can propogate such uncertainty within the model that it can crash the whole model or cause the model to totally fail to even initialize properly. The key to understanding how to properly model a system or predict the behavior of complex systems is in understanding which variables and processes are sensitive to such errors and in the accuracy of the understanding of the relationships between the variables. My skepticism is rooted in the well-documented opinion that we do NOT have enough of an understanding of the long-term climate variability to claim that we can say which variables are important or sensitive to errors and which are not.

1. The Beherenfeld et al. don't look at the climate system. Did you mean to cite something else? And the Walter et al.: we already know this is a feed back to the system. What's your point?

If you read the actual papers, you will see that Behrenfeld et al discovered a discrepency between oceanic plankton concentrations measured by satellite and those measured directly through collection of thousands of water samples. The key finding for our interest is that in the absence of key nutrients in warm water systems, the plankton do not contain as much chlorophyl as previously believed from satellite measurements; and that as a result, the measurements we have relied on to provide whole ocean CO2 uptake values based on plankton concentrations may have overestimated that uptake by as much as 2.5 billion tons per year. With oceanic uptake of CO2 constituting an integral part of the carbon cycle in the atmosphere, overestimating its role could constitute a serious flaw in our understanding of how much CO2 is actually transferred to and from the ocean. I am not saying it DOES...I am saying it could...hence my skepticism.

As for the Walter paper, the conclusion was that methane production from arctic lakes is up to 5 times higher than previously believed. The previous understanding was that it was a feedback, but a relatively insignificant one. But lets let the author speak...

From New Scientist:

"Until now we didn't realise that lakes were such an important source," says Walter.

From the Author Summary at Nature.com:

"Until now, the relative importance of these bubbles has been uncertain because the patchiness of the phenomenon makes it hard to measure...Recent expansion of thaw lakes in the region may have markedly increased methane emissions, suggesting that thaw-lake methane could be a positive feedback to global warming."

When you combine her last sentence with the recent publication of data showing that glacial and polar melting has been occurring at a faster rate since the late 1800s, it calls into question the assumption that the thaw lake feedback has only recently become an important positive feedback. If you listen to what Dr. Dessler said, he pointed out that we can't say with any real certainty what caused the warming from 1860 to 1940 or so, but if we have significantly underestimated the importance of one or more positive feedbacks that could have resulted from that earlier warming, then it has to throw at least some doubt into how well we can estimate what impact can be attributed to human activity from 1940-present.

have simply expressed my doubts that we can determine with certainty how significant that role is or precisely when our influence became significant, when we don't understand the system well enough, as shown in the findings of the VERY recent papers that show that our estimation of oceanic CO2 uptake and arctic lake GHG production are simply WRONG.

Right. Typical argumentation. Denialists have been using this tactic for years.

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If you read the actual papers, you will see that Behrenfeld et al discovered

I love these statements. Let me get the paper and I'll ask you specifics about it to test your comprehension of the paper. I suggest you visit your uni library soon to get this paper.

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Permafrost melting has long been known to be a feedback and has been seriously discussed for at least a decade.

You are focusing on one particular unknown being unquantified - lakes.

I'm unclear as to how this new quantification negates the theory that anthro increases of GHGs results in changing climate. Perhaps I missed that somewhere in your argument.

The key to this, BTW, is that anthro. warming is melting permafrost and releasing CH4, which is a more potent short-term GHG, BTW, albeit with a shorter atm residence time.

The implication of these new data has nothing to do with the amount of increase of CO2 ppmv over the 600K yr baseline that ecosystems and climate system are used to.

Unless, of course, you have some testable hypothesis and data that show there is no effect on climate of increasing atm CO2. Let us know when this blockbuster gets published.

On second thought, you won't have to let us know, because Heritage, CEI, Fox news, et al. will trumpet it to high heaven and you'll be a millionaire from the Heritage Victory Tour speaking fees.

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The planktonic role in the carbon cycle paper has to do with uptake.

This implication has to do with terrestrial (not atmospheric) storage and thus removal from the atmosphere and potential for GHG warming.

I'm unclear as to how this new quantification negates the theory that anthro increases of GHGs results in changing climate. Perhaps I missed that somewhere in your argument.

I am not going to try to have any debate with you on anything from here on out, because you just simply aren't trying to comprehend anything you read. You decided the moment that I expressed dissent from the "consensus" that I was an oil-company hack job that believes global warming doesn't exist and your every comment from that point forward has reflected that 100% incorrect bias. I have explained carefully and in great detail exactly what I felt made those papers important, and precisely how I felt they impacted the understanding of climate change. You ignored everything that I wrote and have posted worthless rebuttals that carry forward your initial assumption that I am trying to deny the reality of global warming or that I am denying any human contribution to GHG concentrations, which anybody with 3rd grade reading comprehension can clearly see that I am not doing. Your trolling must be entertaining for you on some level, but you are not furthering any debate or discussion with your posts here. When you decide to start reading what people write when they have opposing viewpoints and make an honest attempt to comprehend what they are saying, instead of instantly stereotyping them into some "made for a Michael Moore movie" image of the "enemy" in the global warming debate, you will gain a richer understanding of the breadth of scientific opinion and perhaps will even prompt me to start responding to your trolls again...until then, stay safe and Gig'Em.

Mar UK, I am quite familiar with decision making under uncertainty, Monte Carlo simulations, and major component analysis, risk adjusted returns, etc. But if you don't know what the probabilities are for a desired outcome (and you apparently don't even know what the desired outcome is), relative to the costs (risk adjusted), then you are missing major parts of the equation to solve the problem. So would you propose just charging off and doing things without worrying about all those details? If so, perhaps you like our current president and would emulate his philosophies.

This comment was placed previously before Dr. J saying "Mar UK,...", so to reprise:------The REALITY is that climate is persistent only, and if you notice the chart in the link (*) below regarding Glaciations over the past 1 Billion years, you will see that even the Primary Oscillation is presenting a 'shorter (irregular) periodicity' by noticing that the Primary Troughs (within the green blocks being periods in which recurring Glaciations occur) are becoming 'closer'. It IS that 'modern humanity' is but ONE child of 'climate alteration', NOT a cause of such (as yet). The 'current' Polar Ice Sheets are only ~3 Million years 'existent' with any persistence as the present Primary Trough of the overall Climate Oscillation is only ~3 Million 'years old'. Thus there was NOT any seeming 'permanent existence' of these sheets within the previous ~200 Million years of the Primary Crest, again see charts within the link (*) below. The last Glaciation began reverting around 20,000 years ago, the oft mentioned 'little ice age' was a few centuries of depressed 'temperature', one of many within the last 15,000 years, the REALITY being that climate is only ever going to offer persistence within an IRREGULARLY PERIODIC oscillatory NATURAL process.

There is also not any valid link to 'CO2 sources' made in supposition within 'greenhouse science', there is also NOT the 'valid link' of 'CO2' to any possible warming process with regard to the 'greenhouse theory'. If you notice the reality of the warmer ocean surface (slides in link * below), you will see that this trend follows the present Land Surface rise in 'shape' even, lagging by 15 years due to the productions of Conduction and Convection transporting that Kinetic Energy TO the Ocean Surface whilst the muting of that displayed trend is due to internal production of Turbulence in the Ocean surface as reaction to those inputs of Kinetic Energy (this trend is seen in plots at the link * below). As example, there is nothing UNNATURAL in the production of the 'Katrina Event' (as example) that can contain ANY result of 'greenhouse supposition', and ONLY the cumulative effect from the production of Human Habitat Sprawl upon the land surface (related to Human Population growth in its rapid rise from 500 Million to over 6 Billion in ~400 years) can be seen (again with slides in *).

The present Primary Trough, again to mention being only ~3 million years 'long', is occurring after a ~200 Million year long Primary Crest Climate Period. There is little to nil regard for actual (and OBVIOUS) oscillatory Climate Processes within current 'greenhouse climate science' and it is NOT of any value to attempt presentation of 'statistical gibberish & jargon' to pretend to being 'scientific' (as example, isotopical distribution analysis is not able to discern more that the spread of Isotopical forms, this use well known and used widely in SCIENCE (Medicine especially), and cannot tell where the Carbon atom 'came' from when within otherwise 'non-process unique' molecules. CO2 is NOT unique in this REQUIRED manner. Chemical behavioural identicalities tween Isotopical forms is also widely used in MEDICINE.

Temperature is NOT even a valid indicator of supposed UNNATURAL 'Climate Change' in any VALID manner of SCIENCE. When 'temperature' is mentioned, realise that the 'temperature' of a System is that Kinetic Energy residual within the materials constituting that System that is NOT directly involved in the production of the processes of Turbulence within that System. In a System where-in the Mass of the most involved materials contained is proportioned in kilogramsx10^24, then alterations to Turbulence within those materials WILL release (or uptake) vast amounts of Kinetic Energy, and that this will then be observed as a RISE (or DECLINE) in the measured 'temperature' of the System with NO NEED for alteration of the RATE of overall 'new' Kinetic Energy production. Interaction of Oceanic (slower) and Atmospheric (faster) process will see the style of variation of TEMPERATURE seen so far.

It is NOT possible for a 'greenhouse warming process' to even have been existent; the 'greenhouse effect' is inconsistent with the materials it involves as these materials present their ACTUAL behaviours, this is inclusive of those materials presented on the surface as well as with those 'bio-forms' (encapsulated saline water) of surface life as such exists NOW. It is NOT possible for the 'greenhouse theory' to produce in reality a 'warming effect' as it is supposed, with manipulation of Energy within the 'Infrared Region' with regard to the real materials present including those materials involved/contained in 'life forms' and the cellular chemistry exhibited in such. Even the Energy considered within the "Greenhouse rhetorical' is NOT Related to the Temperature of the materials present, these Secondary Photons NOT being 'trapped' but are infact released from those molecules and so represent Non Kinetic Energy. Thus the 'proxy methodology' is ALSO fatally flowed. Again see outlines in link (*) below for further detail.

The platforming of CO2 is very tired and forlorn, one wonders how much longer the 'few' will continue their pantomime activities...in the attempt to avoid real discussion especially with particular notice of needed remediations of Power Generation if it is that wide spread use of Uranium IS to be avoided. There is NOT any 'danger to/from Climate' of any 'unnatural greenhouse style', there never has been and there never will be. Uranium IS however very REAL. After 20 years of 'greenhouse hype', enough IS enough. The study in SCIENCE needed to protect 'life as we know it' needing MORE 'Public notice/concern' is in the production & consistent persistence of the Planetary Dipole (again see link * below).

This comment was placed previously after Dr. J saying "Mar UK,..." & so to reprise the 'mysteriously missing comment':------There is also the initial requirement for a 'problem' to be present if one would even try to validly produce a 'probability'. The REAL and PRACTICAL world does not run on 'hear say and hope'...nor does climate nor those materials behaviours presented and involved none of which will alter their behaviours to accommodate either opinion of belief. Infact the effort to best determine the behavior of Climate is NOT by 'probability' but functional determinations, not using 'standardised distributional analytic forms' (including the oft heard mentioned Normalised Distributional form) but to develop the analytical form OF the Natural Oscillation in a more direct manner. Functional determinations are available in the area of Mathematics nominally labelled Statistical Mathematics one prime analytical form involving the deterministic form of a Time Series.

There is NOT any probability that CO2 can produce a 'greenhouse warming process' as outlined by the 'greenhouse theory', so there is NOT any REALITY in attempting to produce discussion of 'error or correlation management' in a VALID 'deterministic experiment'. There is not either able to be validly produced within validatable SCIENCE an outline of a 'greenhouse effect' that notices the actual properties of CO2 (and the other labelled 'greenhouse gases'). There is not possible therefore, as outlined by the 'greenhouse theory', a 'greenhouse effect' in the REAL 'world' being observed.

'Warming' therefore is not by a 'greenhouse effect', so apart from notice as a portion of 'air pollution' there is little need to notice CO2 (or the other supposed 'greenhouse gases') with any special regard. There is most certainly no 'CO2 forcing' as made mention of in relation to a 'greenhouse' concept. Climate has always been 'changing'; there is as such nothing really to debate about such 'change' being 'existent'. See the link (*) below for 'glacier reborn' outline.

There are numerous sources for materials information, you might look at:-http://www.lsbu.ac.uk/water/h2ovibr.htmlhttp://www.lsbu.ac.uk/water/vibrat.htmlhttp://www.lsbu.ac.uk/water/index.htmlhttp://www.ipr.res.in/~othdiag/fir/stability/node12.html

Solar radiation intensity is a variant of the oscillations of planetary climate, as I have mentioned. The Stellar output of radiation, in spectral division, is coupled with Planetary Axial precession and Orbital Variation to produce a (one example of) trivariant oscillator of the (irregularly periodic) Primary Climate Oscillation. It is not that H20 is an 'amplifier' of 'CO2 warming' but the exact opposite. CO2 (and the other 'greenhouse gases) slow the induction rate of kinetic energy within the atmospheric H2O molecules by intercepting the cascade Photons instead of a H2O molecule.

As each interception allows the Photon the opportunity to take the trended outward (density gradient based) motion the chance of avoiding H2O (held low by the Ice and Condensation Altitudes in interaction with Gravity) is increased for such 'non-H2O events' as Photons trend to be 'lifted' above the H2O region. You need only look at the chart of atmospheric absorbance in the link (*) below to notice the range of the energy interactions of H2O and the materials links to note the dipole behaviours of the H2O molecule will be producing less remittance of energy as Secondary Photons and thus retain more energy as a kinetic alteration of the molecular (unit) velocity. This trait of H2O is at a rate near 100 times that of the CO2 molecule.

The plot for CO2 shows interaction with energy, but much of this energy is reemitted as Secondary Photons, NOT retained as a kinetic energy gain (again related to the dipole behavior of the CO2 molecule). The plot for CH4 and NO2 shows very narrow interactions behavior in comparison, and the molecules have strong remittance trends also. So the H2O molecules actually become directly 'heated' whilst CO2 and the other 'greenhouse molecules' SLOW this process. The Photons reemitted by CO2 and CH4 (as example) do NOT represent 'heat trapping' either, in any valid consideration. 'Heat', measured as Temperature, is the measure of the average kinetic velocity of the molecules (as also is Pressure such another measure) of the 'sample'. The energy reemitted as Photons is separate from the molecules of the atmosphere, even if within the 'boundary region' of the atmosphere.

The suspension of these Photons within the CASCADE formed by the supposed 'greenhouse gases' is simply the suspension of ENERGY. The trended MOTION of these Photons is OUTWARD as the lowering density at increased altitude reduced interception rates. The output of this cascade is records as the "Albedo" of this 'planet'. Increasing the proportion of 'greenhouse gases' will REDUCE the kinetic energy induction (and incidence) rate of H2O molecules (100 times stronger than that of the CO2 molecule) within that portion of the atmosphere BELOW the Water 'Ice & Condensation' altitudes, the Gravity induced rarefication of the atmosphere will reduce such induction rates above these altitudes in conjunction with the reduction in H2O 'molecular population' occurring also.

The planetary Land surface, and alterations to such, is driving both weather patterning alterations and the small rises in median surface temperatures, as previously mentioned. The 'solid surface' cannot shed induced kinetic energy into internal turbulence as readily so expresses such as 'heat' which is conducted into the contacting Ocean and Atmosphere. This is seen in the plot again within the link (*) below.

I don't think commenting on politics is going to move things forward... Like I said, I think the Economist puts is very well by stating that spending a relatively small amount of the global economy on measures is like an insurance policy.

I am not calling for extreme measures here. I think that regardless of whether humans are the cause, part of the cause or have nothing to do with GW, it's happening. So we have to adapt. That doens't mean we should do nothing.

There is NOT any 'market' involvement relevant at all 'Mark UK', it is simply that the 'Kyoto Pantomime' attempts to produce a 'market remediation' for a supposed (but non existent) problem, namely the supposition of a 'greenhouse effect'. As such the 'remediations' of Kyoto are ONLY of interest to those whom can make a fiscal advantage from demanding theory implementation whilst attempting to cite supposed 'profiteering' within those who attempt to point to the shortfalls within those 'Kyoto remediations'.There is Natural Climate change occurring, the LIE is in attempting to overplay a 'greenhouse cause'.